Pro's and Con's of just replacing back box's?

[M@r]{]

Really want a little more sound from the car. I'm not after more power, its fine as it is (although if a side affect is more I won't complain )

I've toyed with the idea of an Induction kit but I'm not convinced. Reading up on M3 Cutters a lot of those guys have done before and after on dynos and see quite large drops in power! (apart from the CSL kit but at £3k+ fook that for an airbox!!)

So I'm considering the less 'risky?' option of just smaller back boxes? Some added benefit is a reduction in weight and the biggy for me, I think the OEM ones look pretty unsightly :roll:

Any thoughts on this? We're literally just talking about the back boxes and tail pipes, as near to OEM pipes as possible (in fact I may talk to them about hacking mine off and using them)

 

[dewarcraig]

IMO -

Pros - miles better looks, lighter, awesome noise!
Cons - price, insurance increase, some types might be considered a chavvy noise :|

I'm with you in that the standard back boxes hang too low and dont look good! I went for the Supersprint race boxes in the end and really like them. They, as i said, look miles better and sound awesome from outside the car. Downside is that they can be a little loud inside the car, probably due to the open trunk/boot to cabin. I'm sure this could be sorted with some sound matting under the boot carpet if required though.

 

[M@r]{]

IMO -

Pros - miles better looks, lighter, awesome noise!
Cons - price, insurance increase, some types might be considered a chavvy noise :|

I'm with you in that the standard back boxes hang too low and dont look good! I went for the Supersprint race boxes in the end and really like them. They, as i said, look miles better and sound awesome from outside the car. Downside is that they can be a little loud inside the car, probably due to the open trunk/boot to cabin. I'm sure this could be sorted with some sound matting under the boot carpet if required though.

Thanks for the feedback. Do you mind me asking how much you paid for them? Any pictures?

I've got a friend who works for Topgear Manchester. He is quite keen to do this for me, and to be honest I know I'll be looked after so tempted to make the trek.

 

[Shooter]

Pro : more noise.
Cons : too much noise, can be annoying on long travel for the driver and his passenger, can be VERY annoying to the neighborghood, might be too loud for track days...
I prefer to go through the induction way.

 

[M@r]{]

Pro : more noise.
Cons : too much noise, can be annoying on long travel for the driver and his passenger, can be VERY annoying to the neighborghood, might be too loud for track days...
I prefer to go through the induction way.

I'm not to bothered about a little extra noise in the cabin (bear in mind I'm used to my Elise and a stupidly loud RX7) The Elise is about perfect and on track days is measured at about 95db at 3/4 revs - static. I estimate the Z4MC is about 86db? (I've got a noise tester at home so I'll measure it when I get a chance)

So better looking, slightly smaller and lighter back boxes but enough sound deadening to prevent getting an ASBO?

I'm nervous about induction kits because of the bhp killing results I've read about, where as changing just the back boxes, ie keeping the cats etc should have very little effect on bhp either way?

 

[Aliv6]

Pros - Potentially lighter and some look good.
Cons - Not heard one that sounds better than stock.

IK in the M sounds good (had a shot in Daz05's) it's deep and throaty at low revs.

 

[mmm-five]

There was a user (Nige BCS of BCS Automotive in St Helens) on here who was talking about a valve-tronic (either vacuum/revs controlled or manually) exhaust system they were developing.

I was going to help them out with initial fitting/trialling, but since my first visit I've not heard from them.

Also posted some info on a previous exhaust thread.

 

[dewarcraig]

M@r]{ - My Supersprint race boxes are defo not loud enough to get an asbo! . My mate just sold his Elise 111R with Lotus race pipes and it was a fair bit louder in the cabin than mine. Mine is louder on tick over but cant say from the outside while driving.

I bought mine s/h off a guy on here and think i paid around £450...

They are a piece of cake to fit and can quite easily be done on the drive tbh.

I like the sound of mine and was always a little disapointed that the std system wasnt a little more lairy. In a perfect world the SS race boxes are a little louder than i would want but I'm happy with them anyway.

I'll take a couple of pics when i get home. I would upload a vid from my iphone too if i knew how...

 

[deedub]

Eisnmann box's are the way to go only a little more noise...deeper at lower rpm and with a great rasp up the top end! But not chav like noise also running Gruppe-m and have noticed a little more push from low down all the way to the top Not massive just feels more responsive :roll:

 

[Booner]

I went for Eisenmann backboxes.
Pros: Deeper, pops and has more character, looks better, not too loud
Cons: Costs me more in fuel as I keep putting my foot down! Slight increase on insurance

I then went for an intake (aFe).
Pros: More noise, brilliant noise, £450 so not as pricey as the carbon jobs or CSL intakes
Cons: None

I really do challenge anyone to notice the very few bhp that you may or may not lose (unproven) via an intake. I'll put my car on the rollers again as I'd be interested in knowing myself.

Do both!

 

[socketr]

I've always liked the staggered tip look on the RPI boxes. Not upto the standard of Akra or possibly even Eisenmann but they sound pretty damn good.

http://www.youtube.com/watch?v=kknbO_ShwGg&feature=fvwrel

 

[ga41]

I've always liked the staggered tip look on the RPI boxes. Not upto the standard of Akra or possibly even Eisenmann but they sound pretty damn good.

http://www.youtube.com/watch?v=kknbO_ShwGg&feature=fvwrel

The RPI's are NOT for everyone though. Extremely loud and you would not believe the drone when they're still new. The drone quiets down a bit after a few thousand miles but the overall volume does not. I like em but they're definitely an acquired taste...

M@r]{ the best option is to go to a big meet with hopefully a couple of different setups to hear for yourself. You say you want a little more sound, well the RPI, the Supersprint Race and the Eisenmann Race will give A LOT of sound... Perhaps something like the Remus system or the Eisenmann Sport?

 

[BMWZ4MC]

Remus backboxes:

Pros:
Deeper tone at idle (where the OEM system really has little character)
Pops maintained (which should be the case with all aftermarket backboxes as the pops and bangs are from the hot end of the pipes anyway) with deeper elements
Fantastic harmonics at 3,500-5,000 rpm, but above this range OEM engine rasp remains audible
Marginally louder, but at 4,000 rpm this remains well below 96dB (measured at 1m and 45 degrees), so should be no problem for even the most conservative track
Very mild drone found only at 100mph in sixth
Not offensive to passengers or neighbours (unless you really provoke it )
Only small visible area of back box, and this is painted black, thus resolving the ugly silver scrotum look of the OEM boxes
Slightly larger pipes, but not chavvy

Cons:
Some may think the sound not loud enough, or even too OEM at higher revs (not problems as far as I'm concerned)
Minimal increase in insurance
Increased fuel consumption for the same reason as Booner - I'm addicted to the sound at 3,500 rpm
May be a bit pricey new, but I bought mine here for a really good price



As you know, I'm thinking about the aFE intake - have you read anything elsewhere about power drops with that system?


Booner, let us know if you've lost power once you've put it back on the rollers.

 

[SweetRide]

Sound aside, there's no power loss with the AFE intake. Marginal gain (if any) but definitely a more responsive throttle. There was some 'definitive' HP loss (2-3) with the 5-series unit, but that's it. Ask anyone who's bought one if they feel it's detracted even 1% from their enjoyment. Most will give u two huge thumbs up

 

[M@r]{]

Sound aside, there's no power loss with the AFE intake. Marginal gain (if any) but definitely a more responsive throttle. There was some 'definitive' HP loss (2-3) with the 5-series unit, but that's it. Ask anyone who's bought one if they feel it's detracted even 1% from their enjoyment. Most will give u two huge thumbs up

Any before and afters on a dyno to back this up? Not being funny just I would love to fall for one of these again

 

[SweetRide]

If there was a 10hp difference either way, I'm sure back to back dyno runs would net the proof ur after; but there's not. You really want to see proof that the two main intakes for our car (within reason - AFE & GruppeM) lose/gain 2hp? Not going to happen. Listen to owners, and see if they'd purchase again and why

 

[M@r]{]

If there was a 10hp difference either way, I'm sure back to back dyno runs would net the proof ur after; but there's not. You really want to see proof that the two main intakes for our car (within reason - AFE & GruppeM) lose/gain 2hp? Not going to happen. Listen to owners, and see if they'd purchase again and why

We're not talking about 2bhp, we're talking about upto 20bhp. If it was 2bhp I'd happily swap that out for a more aggressive noise.

Some examples here:

http://forums.m3cutters.co.uk/showthread.php?t=47400&highlight=induction

http://forums.m3cutters.co.uk/showthread.php?t=48688&highlight=induction

 

[SweetRide]

So u quote tests done on two different (yet same model) dynos? Why didnt it occur to them to run it on the exact SAME unit to somewhat help exclude variables (which certainly are there). Hell, I can go to the same dyno the SAME day and get a 20hp discrepancy.

Regardless, it's all conjecture. If u speak with owners of the GruppeM and AFE units (specifically - not some other garbage)... U will find very few regrets.

 

[Booner]

Happy to go back on the dyno to see what difference it made, I won't be hugely disappointed if it's lower as I really really haven't noticed. Too busy listening to the noise = GRIN FACTOR

 

[BMWZ4MC]

Happy to go back on the dyno to see what difference it made, I won't be hugely disappointed if it's lower as I really really haven't noticed. Too busy listening to the noise = GRIN FACTOR

Yes please... and then the only excuse left for me not to buy one will be the stupid price